MAVEN Reconstructed SPK, NAV Solution, 2017-01-01 to 2017-04-01, Version 1 =========================================================================== Created by Boris Semenov, NAIF/JPL, Thu May 11 14:57:42 PDT 2017 Objects in the Ephemeris -------------------------------------------------------- This SPK file contains ephemeris data for the Mars Atmosphere and Volatile Evolution Mission (MAVEN) spacecraft. The NAIF ID code for MAVEN is -202. Approximate Time Coverage -------------------------------------------------------- This file covers the following part of the orbital phase of the MAVEN mission (orbits 4384 through 4854): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2017 JAN 01 00:01:09.183 2017 APR 01 01:01:09.185 Status -------------------------------------------------------- This file was created by merging regular reconstructed OD solution SPK files produced by the MAVEN NAV team during the orbital phase of the mission. This file was created by NAIF for archiving in the Planetary Data System (PDS). Pedigree -------------------------------------------------------- The original SPK files used to create this file contained only reconstructed trajectory. They were officially delivered to the MAVEN project data base by the MAVEN NAV team. The list of the original files data from which has been merged into this file is provided in Appendix 1 of these comments. Segment Boundary Discontinuities -------------------------------------------------------- This SPK file contains a large number of SPK segments that came from original individual SPK files. Although, each segment provides continuous trajectory within the interval that it covers, in general a position and velocity discontinuity exists at the boundary of the segment and the segments whose coverages immediately precede or follow it. The times and magnitudes of these discontinuities are provided in Appendix 2 of these comments. Usage -------------------------------------------------------- This file should be used together with DE430 planetary ephemeris and MAR097 satellite ephemeris since the original SPK files contained subsets of these particular ephemeris in them. Contacts -------------------------------------------------------- If you have questions regarding this data contact Boris V. Semenov (818)-354-8136 Boris.Semenov@jpl.nasa.gov Appendix 1: Original SPK List -------------------------------------------------------- The original SPK files, the data from which has been included into this file, are: trj_orb_04377-04427_rec_v1.bsp trj_orb_04426-04467_rec_v1.bsp trj_orb_04466-04507_rec_v1.bsp trj_orb_04506-04544_rec_v1.bsp trj_orb_04543-04581_rec_v1.bsp trj_orb_04580-04617_rec_v1.bsp trj_orb_04616-04654_rec_v1.bsp trj_orb_04653-04690_rec_v1.bsp trj_orb_04689-04722_rec_v1.bsp trj_orb_04721-04760_rec_v1.bsp trj_orb_04759-04801_rec_v1.bsp trj_orb_04800-04832_rec_v1.bsp trj_orb_04832-04874_rec_v1.bsp Appendix 2: Segment Boundary Discontinuity Summary -------------------------------------------------------- This SPK file contains a large number of SPK segments that came from original individual SPK files. Although, each segment provides continuous trajectory within the interval that it covers, in general a position and velocity discontinuity exists at the boundary of the segment and the segments whose coverage immediately precede and follow it. The times and magnitudes of these discontinuities are provided in the table included in this Appendix. The top portion of the table contains the name of this SPK file. All descriptive lines in the top portion of the file start with the ``#'' character to allow direct plotting of the data in the freeware ``gnuplot'' application. The table consists of 5 columns. The first column is the orbit number within which a segment boundary with discontinuity occurs. The next column contains the UTC time of that segment boundary. The last three columns (3..5) contain view coordinate frame components -- ``down track'' (this direction is parallel to the velocity vector), ``normal to plane'' (this direction is computed as cross product of position vector by velocity vector) and ``in plane'' (this direction is computed as a cross product of ``down track'' by ``normal to plane'') -- of the difference between the state vectors computed at that UTC time defining segment boundary at which a discontinuity exists. The pairs of segments and discontinuity times are determined using an algorithm that emulates the standard SPK loading priority -- ``last loaded segment takes precedence''. Therefore, the discontinuities summarized in the file are those which a user reading file would actually see. The difference components in the view coordinate frame were computed for each discontinuity using the following algorithm: -- A single state was computed from each pair of segment the J2000 frame at the time of discontinuity. -- For this pair of states, a position difference vector was computed by subtracting the state computed from the segment with higher priority from the state computed from segment with lower priority. Then, a frame transformation matrix rotating these difference vectors from J2000 to the view coordinate frame defined by the state obtained from the higher priority segment was computed, and the position difference vector was rotated to the view frame coordinates using this matrix. The segment boundary discontinuities for this file are: # # Summary of discontinuities at segment boundaries for # SPK file ./maven_orb_rec_170101_170401_v1.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 4384 2017-01-01T02:33:50.816 0.012 0.005 0.028 4389 2017-01-02T03:18:50.816 0.007 -0.002 -0.006 4397 2017-01-03T15:49:35.815 0.006 -0.001 -0.017 4404 2017-01-05T01:58:50.815 -0.020 0.002 -0.071 4414 2017-01-06T23:58:50.815 -0.029 0.001 -0.119 4420 2017-01-08T03:58:50.815 0.024 0.004 0.110 4426 2017-01-09T05:58:50.815 0.005 -0.002 0.017 4433 2017-01-10T14:52:41.815 0.023 -0.006 0.138 4440 2017-01-11T21:41:12.815 -0.015 0.007 0.018 4445 2017-01-12T21:58:50.815 0.019 -0.005 0.163 4453 2017-01-14T11:43:50.815 0.001 0.000 0.018 4457 2017-01-15T04:28:50.815 0.004 -0.002 0.047 4462 2017-01-16T03:58:50.815 -0.005 0.001 -0.108 4466 2017-01-16T21:28:50.815 -0.004 0.002 -0.076 4470 2017-01-17T15:28:50.815 -0.000 0.000 -0.015 4476 2017-01-18T18:58:50.815 -0.002 0.001 -0.011 4480 2017-01-19T13:38:50.815 -0.007 0.004 0.077 4487 2017-01-20T21:10:50.815 -0.006 0.002 -0.059 4495 2017-01-22T11:58:50.815 0.016 0.002 -0.160 4499 2017-01-23T05:23:50.815 0.007 -0.003 -0.048 4506 2017-01-24T13:33:50.815 -0.002 0.001 0.009 4514 2017-01-26T02:43:50.815 -0.011 0.001 0.055 4524 2017-01-27T22:43:50.815 -0.001 0.001 -0.004 4527 2017-01-28T13:58:50.815 -0.001 0.000 0.004 4530 2017-01-29T05:02:27.815 -0.020 -0.008 0.084 4535 2017-01-30T01:58:50.815 0.002 -0.001 -0.002 4538 2017-01-30T15:07:37.815 0.001 -0.000 0.001 4543 2017-01-31T14:03:50.815 -0.058 0.030 -0.030 4548 2017-02-01T14:58:50.815 -0.016 -0.002 0.048 4554 2017-02-02T16:13:50.815 0.019 -0.009 0.028 4560 2017-02-03T20:58:50.815 0.031 -0.008 -0.054 4564 2017-02-04T15:58:50.815 -0.022 -0.002 0.047 4572 2017-02-06T04:28:50.815 0.013 0.000 -0.025 4580 2017-02-07T17:05:50.815 -0.010 -0.001 0.017 4587 2017-02-09T01:03:50.815 0.069 -0.002 -0.106 4596 2017-02-10T18:13:50.814 -0.040 0.001 0.052 4601 2017-02-11T16:43:50.814 -0.007 0.002 0.007 4608 2017-02-13T01:13:50.814 0.009 -0.000 -0.010 4616 2017-02-14T14:28:50.814 -0.011 -0.003 0.015 4623 2017-02-15T20:58:50.814 0.000 -0.000 0.000 4628 2017-02-16T20:58:50.814 -0.032 -0.002 0.032 4634 2017-02-17T22:28:50.814 0.032 -0.014 0.030 4642 2017-02-19T13:18:50.814 0.105 0.020 -0.100 4645 2017-02-20T00:58:50.814 -0.068 0.034 -0.045 4649 2017-02-20T20:48:50.814 -0.055 0.004 0.036 4653 2017-02-21T14:08:37.814 0.094 -0.045 -0.003 4661 2017-02-23T03:12:06.814 -0.252 0.080 0.082 4670 2017-02-24T20:31:05.814 0.148 -0.038 -0.051 4674 2017-02-25T13:13:50.814 -0.019 0.004 -0.016 4679 2017-02-26T13:08:50.814 0.020 -0.009 0.000 4684 2017-02-27T12:48:50.814 -0.069 0.010 0.025 4689 2017-02-28T11:58:50.814 0.062 -0.000 -0.028 4695 2017-03-01T14:58:50.814 -0.052 0.011 0.014 4702 2017-03-02T22:58:50.814 0.065 -0.015 -0.014 4711 2017-03-04T15:58:50.814 -0.039 0.012 0.005 4715 2017-03-05T09:58:50.814 -0.075 0.032 -0.001 4721 2017-03-06T14:18:50.814 -0.084 0.004 0.023 4731 2017-03-08T11:08:50.814 0.053 -0.023 0.002 4737 2017-03-09T14:48:50.814 -0.191 0.069 0.005 4743 2017-03-10T19:38:50.814 0.045 0.012 -0.015 4752 2017-03-12T12:08:50.814 0.199 -0.007 -0.033 4759 2017-03-13T20:28:50.814 -0.016 -0.002 0.003 4763 2017-03-14T13:13:50.814 0.024 -0.012 0.004 4771 2017-03-16T02:28:50.814 0.012 -0.004 -0.000 4780 2017-03-17T20:45:07.814 0.067 0.015 -0.011 4785 2017-03-18T17:13:27.814 -0.063 0.024 -0.015 4789 2017-03-19T12:59:57.814 -0.034 0.008 0.001 4795 2017-03-20T16:08:10.814 -0.005 0.002 -0.000 4800 2017-03-21T14:58:50.814 -0.175 0.062 -0.001 4803 2017-03-22T03:43:50.814 0.078 -0.039 0.011 4810 2017-03-23T14:43:50.814 -0.035 -0.016 0.004 4817 2017-03-24T21:58:50.814 0.040 0.005 -0.003 4826 2017-03-26T14:58:50.814 -0.081 -0.012 0.003 4832 2017-03-27T15:58:50.814 -0.010 0.004 -0.000 4837 2017-03-28T14:48:50.814 0.001 -0.000 0.000 4843 2017-03-29T21:48:50.814 0.005 0.001 0.000 4847 2017-03-30T13:58:50.814 -0.027 0.008 0.001 4854 2017-03-31T21:58:50.814 -0.012 0.004 0.000 End of comments.